Centrifugal separator



Nov. 26,1940.

- G. D. ARNOLD CENTRIFUGAL SEPARATOR Filed April 14, 1939 2 Sheets-Sheet l INVENTOR.

AM,%MM

, ATTORNEYJ Gee/94o Z7. ABA/04D I Nov. 26, 1-940. (5. D. ARNOLD CENTRIFUGAL SEPARATOR Filed April 14, 19:59

QSheets-Sheet 2 I 1 N VEN TOR.

6EPAO [196N040 M,W mib ATTORNEYS:

Patented Nov. 26, 1940 l v 7 UNITED STATES PATENT OFFICE CENTRIFUGAL SEPARATOR Gerald Arnold, Wauwatosa, Wis.

Application April 14, 1939, Serial No. 267,933 14 Claims. (01. 183-83) This invention relates to improvements in cen- Fig. 1 is a vertical axial section through one trifugal separators. embodiment of the present invention.

It has particular reference to the type of sepa- Fig. 2 is a plan view of a circular dished bafll rator known as a collector and used at the terplate, located in the lower part of the outlet minus of a pneumatic conveyor to separate from chamber.

the air-stream the material carried thereby, and Fig. 3 is a horizontal cross section view taken can be used with minor modifications for the along line 33 of Fig. 1.

separation of solids from liquids. P Fig. 4 is a view in perspective of the airdis- My primary object is the elimination of eddy charge pipe and its enclosingre-entry cylinder.

currents in a centrifugal separator of the re- Fig. 5 is a fragmentary cross sectional view of circulating type. It is my purpose to provide a the inlet pipe as it partially enters the cylinder,

' separator which will accomplish with a high detaken along the line 5-5-of Fig. 3.

gree of efiiciency the separation of dust or other Fig. 6 is a fragmentary cross sectional view of light weight particles from the air stream by a the inlet pipe and cylinder, taken along line 66 process of skimming the relatively pure. air from of Fig, 3.

the inner surface of the vortex and returning for r Fig. '7 is a fragmentary sectional view of the re-separation, with a minimum of interference skimming cone l8 taken along line 1-1 of Fig. 1'. with the vortex, air which entrains fine particles Like parts are identified by the same reference of solids. characters throughout the severalviews.

While various expedients have been proposed .to The general form of the collector is similar to increase efliciency by a divergence of that porthat of other devices in that the collector has an mm of the fluid which has still a relatively high inlet pipe 8 leading tangentially into a cylindrical content of solids back into the path of the inchamberll, at the base of which is a tapering dis coming fluid, my invention relates to an improve charge throat l0 leading downwardly therefrom ment in the method by provision'of an internal to a spout 14 through which is discharged the return in place of an external return, and to other Solid materials during the operation of the device. novel and useful improvements as follows. The discharge pipe it through which the air I propose to provide a means whereby the asescapes, is centrally locatediin the upper cylin-' cending center air column is skimmed of solids drical portion of the device and may be capped at its base as well as at'the opening-of the air as shown at l2 for the double purpose of reducing '30 discharge pipe; if V the velocity of discharged gases and to protect I further propose tominimize' the eddy curthe interior of the device'from the weather.

rents which, in the conventional type separator, The fluid containing the material to be sepa originate in the vortexof the discharge chamber rated enters the inlet pipe under ressure." The and ascend, entraining'solid. particles which have vortex necessary for centrifugal separation is been previously separated from the air stream. started in the inlet pipe, the outer portidncf A furtherobjec't is to provide an intermediate which is arcuately curved on a-gradually' reducsleeve which surround the discharge pipe in a in radius to form a tangenti l inlet passage parmanner providing an annular airpassage through tially shown at 1 l3. The'air stream follovvSthe jacent'the outSmeseParatBrwaH.

which that 'w ex containing light periphery of the cylinder 9 and spiralshe'lically' 4 dust ascends tolthe topbf'thg device and downwardly into the tapering discharge cham ters the i com n fluidijbeing" protected during 'i' .centnmgal m throws the ascent'from 'thede'sbendi g'vortexcurrents ad- 9 against the thechamPer where'they' spn'al down to the removal spout-f4; At apoint' The separation @of light dust, is accomplished theremwalimut a h pressured? with more dimcultyf than is the separation of dust exists clueito-thelairstreairrli bemgconfinedto an laden with heavier particles. Thevortex becomes 22222 3 5 3 2? bgggig? i, :1 einds h M 'cran posie itltii i ltiiii iiihiil ifafitfifi iiri iii above spout air upwardlyinl V spiraling column. toward a low pressure area :at rises at the center .Of the-vortex d S d a Out the base of discharge pipe H. v Centrally and ade the air discharge pipe -and only comparatively j ustably mounted at thisposition and provided 5 lightdustenters the annular passage and is rewith a multiplicity ofradially extending louvers turnedto'the inlet stream. a 1 l6 opening against thedirection of the vortex, is, In thagawings: a recessed or dished baiile plate IS. The form of the cylinder.

an upward path without eddies, and without permitting the vortex to entrain previously separated solids which may be settling down the periphery of the discharge chamber l0. Louvers l6 permit solids which are thrown against the baflle plate by the sudden change of direction of the air in the vortex to pass through the baffle and down toward the removal spout 14. Solid material is aided in passing to spout l4 by the spiraled fin ll leading downwardly, alongthe walls of the dischargechamber 1.0 .50 as to prevent disturbance. The relatively pure air escapes from the rising column at the center of the vortex through the discharge pipe ll. Adjustably and centrally placed near the bottom open end of the air discharge pipe is cone l8, apex inverted, the sides of which are provided with a multiplicity of louvers [9 to act as a skimming device by passing the relatively pure air at the center of the whirling ascending column.

Placed radially in the discharge pipe II are a plurality of radial fins 20, preferably four, so secured that they form a support for the upper end of rod 2|, which in turn acts as support for cone l8 and baille I5, the lower end of rod 2| being supported by bracket 2"). As the whirling column ascends centrally and approaches the air discharge pipe, skimming cone l8 performs the double function of diverting outwardly the fluid containing fine dust and allowing the pure air to escape up the discharge pipe, means for said escape being provided by the multiplicity of radially extending skimming louvers l9 which open against the direction of the vortex. As the whirling column of pure air ascends the discharge pipe II, it encounters baiiie plates 20 which stop all whirling motion. When the whirling central column, as; explained above,

ascends to the skimming cone, the fluid entraining fine dust being heavier, is at the outside and tends to remain in spaced relation to the cone. Encircling the discharge pipe I I an intermediate sleeve 22, secured centrally to the top of cylinder 9, extends downwardly and opens into the cylinder, 9 at a point somewhat below the air discharge cylinder, thus providing an annular column through which the fluid entraining fine dust passes simultaneously with the passing of the pure air up the discharge pipe. A section 24 of the upper wall of sleeve 22 is depressed to form passage 23 through which 'the air re-enters cylinder 9 at a point tangentially located at the inner periphery of the annular separating space opposite the point at which the inlet pipe joins The ascending dust laden fluid passes through this opening and joinsthe incomingrfluid to repeat'the cycle. In this manner the partially cleansed fluid is returned and only the purest component in each cycle is able to escape through the air discharge pipe.

There exists a definite correlation between the maximum emciency of the separator and the axially spaced relation of base 26 of discharge pipe ll to v the lower end 21 of sleeve 22. This relationship is a. variable factor dependent upon the type of material to be separated, and as one efliciency for any material likely to be intro-' duced in the separator, pipe II has axially extending slots 28 through which bolts 29 extend to adjustably fasten pipe II to annular bracket 30,

saidfbracket being secured to the .casing of chamber 9.

2,222,930 -ba flle plate- IE is such that it starts the vortex on I claim:

1. A centrifugal separator comprising the combination with a casing having a tangential inlet for establishing a vortex of predetermined direction therein, of an air discharge pipe opening upwardly to the atmosphere from a position near the center of the casing, a sleeve surrounding said pipe and spaced therefrom to provide a supplemental air passage, said sleeve having an outlet port opening to said casing adjacent said inlet whereby the vortex rotation in said casing will aspiratematerial from said passage for the recirculation thereof in said vortex, and a baflle at the mouth of said discharge pipe within said casing provided with restricted openings for passing to said pipe the relatively pure air at the center of said vortex, said baflle 'being adapted to assist in directing dust bearing air inlet whereby the vortex rotation in said casing will aspirate material from said passage for the recirculation thereof in said vortex, and a baflle at the mouth of said discharge pipe within said casing, said baille having a relatively wide portion substantially filling the mouth of said pipe and being thence tapered downwardly to a point below said mouth and having a slotted tapering wall provided with louvers projecting opp sitely to the direction of vortex rotation, whereby to be adapted to pass to said pipe the relatively pure air at the center of the vortex while establishing a relatively eddyless movement of dust bearing air to said passage for recirculation.

3. In a centrifugal separator, the combination ,with a casing having a. portion generally circular in cross section, of an inlet pipe disposed in a direction generally tangential with reference to said circular portion and offset radially therefrom, said casing having an enlarged portion providing a channel constituting an extension of the outer surfaces of said pipe and gradually decreasing in radius to merge, spirally with saidcircular casing portion, a discharge pipe opening centrally from the first mentioned portion of said casing and extending upwardly into coinmunication with the atmosphere, and a recirculating sleeve surrounding said discharge pipe in spaced relation thereto and provided with a return out let to the upper portion of said casing opposite the channeled portion of said casing whereby material rising through said sleeve is aspirated for recirculation in said casing.

- 4. In a centrifugal separator, the combination with a casing having a portion generally circular in cross section,- of an inlet pipe disposed in a direction generally tangential with reference to said circular portion and offset radially therefrom, said. casing having an enlarged portion providing a channel constituting an extension of the outrsurfaces of said pipe and gradually decreasing i radius to merge spirally with said circular casin 1 portion, a discharge pipe opening centrally frog the first mentioned portion of said casing and e tending upwardly into communication with tli atmosphere, and a recirculating sleeve surround ing said discharge pipe in spaced relation there.

to and provided with a return outlet to the upper portion of said casing opposite the channeled portion of said casing whereby material rising through said sleeve is aspirated for recirculation in said casing, said discharge pipe being provided adjacent its mouth with a conical baflle substantially filling the mouth of the pipe and having its apex directed downwardly therefrom, said baflle having side portions provided with generally radial slots and louvers expressed outwardly from said baiiie and opposed to the direction of vortex rotation in said casing, whereby to skim from dust laden air entering said sleeve to relatively pure air adjacent the vortex center for discharge through said centrally opening discharge pipe.

5. In a device of the character described, the combination with a casing having a closed top and a generally tangential inlet, ofa discharge pipe opening centrally from said casing and leading upwardly through said closed top to com municate with the atmosphere, said pipe being connected with said top for support therefrom, a sleeve suspended from said top and surrounding said pipe and provided immediately below said top with an opening leading to said casing adjacent the level of said inlet, radial baflie means within said pipe constituting a supporting spider, a rod connected with said spider, and a baiile substantially closing the mouth of said pipe and adjustably mounted on said rod to receive support from said spider, said baffle being provided with generally radial slots and skimming louvers outwardly directed in opposition to the movement of the vortex produced in said casing by said tangential inlet.

6. In a device of the character described, the combination with a casing having a closed top and a generally tangential inlet, of a discharge pipe opening centrally from said casing and leading upwardly through said closed top to communicate with the atmosphere, said pipe being connected with said top for support therefrom, a-

sleeve suspended from said top and surrounding said pipe and provided immediately below said top with an opening leading to said casing adjacent the level of said inlet, radial baflie means within said pipe constituting a supporting spider, a rod connected with said spider, and a baflle' substantially closing the mouth of'said pipe and adjustably mounted on said rod to receive support from said spider, said bafile being provided with generally radial slots and skimming louvers outwardly directed in opposition to the movement of the vortex produced in said casing by said tangential inlet, said sleeve having its lower end disposed at a level in said casing lower than the mouth of said pipe, and said baiile having a downwardly directed conical apex.

'7. A centrifugal separator comprising the combination with a casing having a generally tangential inlet, of an outlet pipe opening centrally from said casing and extending upwardly therefrom, a spider mounted in said outlet pipe and constituting a baiile, a rod depending from said spider, a discharge throat for solids extending downwardly from said casing and provided with a rod positioning spider wherein said rod is engaged, and a skimming baflle mounted on said rod adjacent the mouth of said pipe and provided with louvered vents afiording access to the interior of said pipe.

8. In a centrifugal separator, the combination with a casing having a downwardly tapering discharge throat, of a dished bathe in said throat having its upwardly flaring marginal portions in spaced relation to said throat and extending thence downwardly and recurvently upward at a central apex, said baflle being provided with louvered slits in its recurvent portion for passing toward the discharge portion of said throat solids 5 centrifugally displaced toward said baflle in the sudden change of air direction effective thereby.

9. In a device of the character described, the

combination with a casing having a closed top and a generally tangential inlet, of a discharge pipe opening centrally from said casing and leading upwardly through said closed top to communicate with the atmosphere, a sleeve surrounding the portion of said pipe within the casing to extend substantially therebelow, and provided 15 immediately below said top with an aperture opening directly into said casing adjacent the ably mounted on said throat and provided with an upwardly flaring margin spaced from said fin 30 and a downwardly depressed intermediate portion upwardly recurventtoward a central apex, said depressed intermediate portion having slits and skimming louvers for passing solids while deflecting gases upwardly substantially without eddies at the summit of the casing vortex.

11. In a separator, the combination with an outer casing having an inlet tangential to and leading into the upper portion of the casing and an air discharge tube projecting through the top 40 casing wall centrally thereof and extending substantially into the casing; of a sleeve enclosing the housed portion of the discharge tube in spaced concentric relation thereto, said sleeve having an inwardly pressed wall portion whereby to con- 45 stitute a passage communicating tangentially with the casing in the direction of inlet material travel.

12. In a separator, the combination with a casing having a substantially tangential inlet and so a centrally located discharge tube, a portion of which projects within the casing, of a recirculating sleeve disposed within the casing and encircling the projecting portion of the discharge tube in spaced relation thereto to provide a passageway intermediate the tube and the sleeve to receive an ascending vortical current, said sleeve being provided with an aperture opening to the interior of the casing adjacent the inlet to provide communication wholly within the casing between the passageway and the space intermediate the recirculation sleeve and the casing wall whereby the vortical current and entrained particles rising in the passageway pass through said aperture and the particles become re-entrained in the incoming stream.

13. In a separator, the combination with a casing having an inlet and a centrally located air discharge tube having a portion projecting within the casing, of a recirculating conduit including a sleeve in spaced relation to that portion of the discharge tube located within the tube, and extending below the lower end of the casing, and a skimming cone concentrically disposed with apex downward in the casing terminus of the discharge tube whereby the space defined between upper portions of the cones periphery and the lower inner wall of the recirculating conduit provides ahaving upwardly flaring marginal portions in spaced relation to said throat and extending thence downwardly and recurvently upward at a central apex, said baflle being provided with radially positioned louvered vents opening against 5 the direction of vortex rotation.

GERALD D. ARNOLD. 

